Locking device for well tools

Claim 1

A WELL TOOL FOR USE IN A FLOW CONDUCTOR PROVIDED WITH A PAIR OF LONGITUDINALLY SPACED OPPOSITELY FACING STOP MEANS, SAID WELL TOOL INCLUDING: A BODY HAVING STOP MEANS FOR ENGAGING ONE OF SAID STOP MEANS OF SAID FLOW CONDUCTOR TO LIMIT MOVEMENT OF SAID WELL TOOL IN ONE DIRECTION THROUGH SAID FLOW CONDUCTOR; AN EXPANDER MOUNTED ON SAID BODY FOR LONGITUDINAL MOVEMENT THEREON BETWEEN AN OPERATIVE POSITION AND AN INOPERATIVE POSITION, SAID EXPANDER HAVING AN EXTERNAL RETAINER SURFACE, AN EXTERNAL LOCKING SURFACE OF GREATER DIAMETER THAN SAID RETAINER SURFACE, AN EXTERNAL EXPANDER SURFACE EXTENDING OUTWARDLY AND IN A SECOND DIRECTION OPPOSITE SAID ONE DIRECTION FROM SAID RETAINER SURFACE TO SAID LOCKING SURFACE, AND A STOP MEANS; AND A SUBSTANTIALLY ANNULAR LOCKING MEMBER CARRIED BY SAID BODY AND DISPOSED ABOUT SAID EXPANDER, SAID LOCKING MEMBER BEING POSITIONABLE BETWEEN SAID SPACED STOP MEANS OF SAID FLOW CONDUCTOR WHEN MOVEMENT OF THE WELL TOOL IN SAID ONE DIRECTION IN SAID FLOW CONDUCTOR IS ARRESTED BY ENGAGEMENT OF SAID STOP MEANS OF SAID BODY WITH SAID ONE OF SAID STOP MEANS OF SAID FLOW CONDUCTOR, SAID LOCKING MEMBER BEING RADIALLY EXPANDABLE, SAID BODY HAVING MEANS ENGAGEABLE WITH SAID LOCKING MEMBER FOR LIMITING MOVEMENT OF SAID LOCKING MEMBER IN SAID ONE DIRECTION RELATIVE TO SAID BODY, SAID LOCKING MEANS BEING IN RADIALLY RETRACTED POSITION WHEN DISPOSED ABOUT SAID RETAINER SURFACE AND IN RADIALLY EXPANDED POSITION WHEN DISPOSED ABOUT SAID LOCKING SURFACE, SAID LOCKING MEMBER BEING MOVED BY SAID EXPANDER SURFACE FROM SAID RETRACTED POSITION TO SAID EXPANDED POSITION WHEN SAID EXPANDER IS MOVED LONGITUDINALLY IN SAID ONE DIRECTION RELATIVE TO SAID BODY FROM SAID INOPERATIVE POSITION TO SAID OPERATIVE POSITION, SAID STOP MEANS OF SAID EXPANDER LIMITING MOVEMENT OF SAID LOCKING MEMBER IN SAID SECOND DIRECTION ON SAID EXPANDER.